Method of and apparatus for making incandescent lamps and similar articles



y 23, 1929. R. F. STRICKLAND 6 METHOD OF AND APPARATUS FOR MAKING INCANDESCENT LAMPS AND SIMILAR ARTICLES Filed D90. 1.926

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Patented July 23, 1929.

UNITED STATES 1,722,161 PATENT OFFICE.

ROYAL F. STRICKLAN D, OF CLEVELAND HEIGHTS, OHIO, ASSIGNOR TO GENERAL ELEC- TRIO COMPANY, A CORPORATION OF NEW YORK.

mn'rnon or AND APPARATUS FOR MAKING INCANDESOENT LAMrs AND SIMILAR narrows.

. Application filed December 4,1926. Serial No. 152,700.

My invention relates to the manufacture of devices which comprise a transparent containerand which are subjected to heat during said manufacture. A specific example is the manufacture of electric incandescent lamps and similar devices which comprise a bulb ordinarily of glass and which are, evacuated or gas-filled commercially on a machine which receives a number of them at one time. The temperature during such evacuation or gas-filling must be carefully regulated in order to obtain the best results.

According to my invention, my improved temperature indicating device is sealed into a bulb or other similar transparent container and an assembly is thereby produced which is similar to the other assemblies treated by the machine. As the aforesaid assembly of bulb and indicating device progresses through the machine, it gives a reliable indication of the temperature in the other assemblies. It will be obvious that such a device will be useful wherever the matter of temperature is important regardless of the nature of'the machine or its function.

In the manufacture of incandescent lamps, according to one practice, the glass stem or mount which carriers the filament is fused into the neck of the glass bulb on a separate sealing-in machine such as that shown in United States patent to Mitchell and White, No. 1,453,594, May 1, 1923. The sealed-in lamp is then transferred to an exhaust machine such as that shown in United States patent to Massey No. 996,936, July 4, 1911. According to more recent practice, the sealing-in and exhausting operations are both performed on 'a single machine, such as the type disclosed in the applicationof Patterson, Serial No. 7 08,240, filed April 22, 1924. On this machine the lamps are heated prior to exhausting on the sealing-in portion of the machine and transferred while still hot to the exhausting portion thereof. While, according to former practice, a heater was provided for the lamps in the exhaust machine, accordin .to more recent practice, the sole heat is rnished during the sealing-in operation. In order to obtain uniform results in exhausting, the temperature of the lamps should be uniform. Gonsiderable difficulty has been experienced in controlling the temperature of the lamps during the sealing-in operation. My invention provides a method of accomplishing this, and also a suitable apparatus.

Considered, from one standpoint, my invention comprises an improvement in the methods of manufacture of incandescent lamps and similar electrical devices comprismg sealed containers. Such improvement consists in supplying the articles at ,a uniform temperature tothe apparatus which is to perform the exhausting or gas filling operation so that said operation may be performed without the necessity of further.

' and similar devices, and which isefiicient in operation and easily mounted. Various other features and advantages will appear from the description whichfollows of a species thereof.

My invention will best be understood in connection with the accompanying drawings, in which Fig. 1 is afront elevation of my indicating device mounted upon an ordinary incandescent lamp stem; Fig. 2 is a side elevation thereof; Fig. 3 shows the device sealed into an incandescent lamp bulb,

a portion of-Which is broken away for clear-,

ness; Fig. 4 is a vertical section on a large scale along the line 44 of Fig. 1; and Fig. 5 is a fragmentary elevation of an incandescent lamp making machine, showing the indicating device in the process of assembly and operation.

- Referring now more in detail to my invention as illustrated, the indicating' device as shown comprises adifi'erential expansion spiral strip 10. The strip 10 issupported by means of a horizontally disposed pin 11 which extends through an aperture 12- formed in the plate 13. At the outer end of the spiral stri is attached a radial wire pointer 14 wh ic is caused to travel between points calibrated upon the face of the plate 13 when the said strip is affected by temperature changes. In attaching the strip to the plate, it is important that the pointer 1 1-- be accurately placed with respect to the points on the face'of the said plate and by rotating the pin 11, this adj ustment is taken care of after which thesaid pin is securely clamped to the plate by means of the binding screw 16. The plate 13 may be supported, as shown, upon an ordinary incandescent lamp stem 17, the arbor rod 18 of which extends through an aperture 19 formed in the extension 20 of the said plate.

To obtain a Imore secure attachment, the leading-in wires' 21 and 22 are passed through the holes 23 and 24 formed in the extension 20 and then bent over. After the various elements of the indicating device have been properly assembled,adjusted and attached to the stem 17, as shown in Figs. 1

to 33 inclusive, the assemblyorinount as a whole is placed on a sealing-in machine and sealed into a bulb.

In Fig. 5 is shown a fragmentary elevation of a high speed lamp making machine such as the type disclosed in the application to Patterson hereinbefore referredto. sThis A glass bulb 32 isv then placed over the -mount and supported by a yoke 33 so that the parts are in the relative position as shown. The carrier is then intermittently rotated so as to carry the'sealing-in heads 26 in succession by a number of stations at which are located the sealing-in burners 27 which fuse the neck of the bulb to the flange end of the mount 29. In addition to the burners 27 are burners 34 which are arranged to direct their flames upon certain portions of the bulb so as to properly heat it and prepare it for exhausting. When the head containing the sealed lamp returns to the load ing position, the operator removes the lamp and inserts the end of. its exhaust tube 31 in one of the exhaust heads-35, as shown in Fig. 5, and it is then ready to be exhausted. This transfer of the lamp from the sealing-in head to the exhaust head is accomplished quickly, and the heat supplied by thesealingin and additional bulb heating fires should be such that no additional heating during exhaust will. be required.

According to my invention, when it is desired to determine the temperatures reached and the parts are sefit around the machinev as in lamp making. The temperature to which the bulb is'subjected at the various stations affects the differential expansion strip10 so as to cause the pointer 14 to move along the calibrated face 15 of the plate 13.

If it'is found that the temperature is too high or too low, the burners 27 and 34 are adjusted.

An indicating assembly may be sentaround the machine from time to time and removed at the end of each revolution or an assembly of bulb and indicating device may be used repeatedly. In the latter case, after the first revolution, it is desirable to place a shield 36, preferably of metal, over the seal portion 37 of the bulb so as to prevent the sealing fires from softening it. The shield-.may be conveniently attached to the bulb by means of the integral spring fingers 38 which project into the stem 17.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The method of making incandescent lamps and similar devices which comprise parts sealed into a-bulb or similar container which consists in performing the sealing-in operation upon a succession of assemblies of lamps, with which is included a blank comprising a bulb and a temperature indicating device located inside of said bulb, and

regulating the temperature of such assemblies according to the indications thus obtained so that successive assemblies have a substantially uniform temperature at the end of the sealing-in operation.

2. The method of making incandescent lamps and similar devices in the manufacture of which parts are sealed into' a bulb which is subsequently exhausted, which consists in regulating the temperature of a succession of such devices during. the sealing-in operation by measuring the temperature inside of a bulb subjected to the same operation and adjusting the fires accordingly, delivering each of the devices successively at a substantially uniform time interval to the exhausting operation, and performing the exhausting operation without further supply of heat.

In witness whereof, I have hereunto set my hand this 2nd day of December, 1926.

ROYAL F. STRICKLAND. 

